johnson



(No Model.) E. H. JOHNSON.

TELEPHONE. No. 443,526. Patented Dec. 30, 1890.

1 U WW I UNITE STAT-Es PATENT Fries,

EDIVARD ll. JOHNSON, OF NEW YORK, Y.

TELEPHONE.

QPECIFICATION forming part of Letters Patent No. 443,526, dated December30, 1890.

Application filed April 24, 1884. Serial No. 129,065. (No model.)

T0 at wit/0121, it may concern.-

Be it known that I, EDWARD H. JOHNSON,

of New York city, in the county and State of New York, have invented acertain new and useful Improvement in Telephone-Transmitters, of whichthe following is a specification.

The object I have in view is to produce a telephone-transmitter fortransmitting articu late speech, capable of use directly in the line,which may be kept constantly charged by a battery located at either endof the line or at the exchange or central office, and proportioned tothe length of the line. In this way a telephone-exchange system could beproduced wherein nobatteries would be required at the subscriberstelephones and no induction-coils would be necessary, the transmittersacting directly upon a line-current of constant direction to vary it bythrowing it into pulsations practically in unison with the soundwaves.The receivers would also be directly in the line, and since the linewould be constantly charged simple electromagnetic receivers could beemployed, the diaphragms being kept under tension by the constantcurrent, and no permanent magnets being required for that purpose. Theinstrument is designed to produce great variations in the line-current,similar to those produced by a telegraph-key, and hence by properlyproportioning the transmitter and receiver to the resistance of the linethe same length of line may be used as in telegraph systems, and thetelephone system will be reduced to the simplicity of arrangementemployed in the present Morse telegraph. The deleterious effects ofinduction from adjoining lines will also be overcome.

While my transmitter has advantages of being adapted for the useexplained, it is also capable of use with induction-coils, like thecarbon transmitter, when proportioned or connected properly for suchpurpose.

The invention covered by the present application for patent is limitedto the telephone-transmitter per se, however it may be used.

In carrying out my invention I make use of a number of independent andfree circuitcontrollers acted upon independently by the sound-waves andfree to move in unison with the condensations and rarefactions of theatmosphere produced by the vocal organs. These circuit-controllers serveto vary the number of definite units of current in the telephone-circuitby changing the number of definite units of resistance or counterelectromotive force in circuit, or both.

For my instrument I employ for each circuit-controller the arrangementshown and described in my patent, No. 381,382, dated April 17, 1888, orany modification thereof covered by such application, and mount a numberof these circuit-controllers in one i11- strument, with the heads of thepiston soundwave receivers in a common sound-wave-receiving chamber. Themagnet or solenoid coils are connected in any desired arrangement ofseries, multiple series, or multiple arc in one circuit, which may bethe line-circuit or the primary of an induction-coil. I arrange all theindependent circuit-controllers so that they are all situated atdifferent distances from the central point. I prefer an arrangement inthe form of a geometrical spiral. I find that this arrangement of thecircuit-controllers, so that they are all at different distances fromthe central point, gives the best results in the transmission of speech,and I believe this to be due to the fact that there is a progressiveaction of the different circuit controllers.

In the accompanying drawings, forming a part hereof, Figure 1 is a frontview of the instrument, the door of the inclosing-box being thrown open;Fig. 2, a side elevation of the instrument with the inclosing-box insection; Fig. 3, a view from the rear of the instrument; Fig. 4C, asectional view, on an enlarged scale, of one piston sound-wave receiverand the parts connected therewith; Fig. 5,a vertical section of four ofthe piston sound-wave receivers arranged in two series, and Fig. 6 arepresentation of the current-pulsations caused by the instrument whenused directly in line.

In the block A, of hard rubber or other suitable insulation, are mounteda number of the independent circuitcontrollers having the arrangement ofa geometrical spiral, as shown in Figs. 1 and 2. Each is composed of anelectro-inagnet B, a piston sound-wave receiver G, carrying armature a,and guided and retarded in its movement, and points I) c,

of platinum or other suitable metal, carried by the magnet and armature,as shown,these parts being more particularly described in my patent, No.381,382, dated April 17, 1888.

Each magnet B is carried by the hollow end of aplug D, of hard rubber orother suitable insulator, having an enlarged head which fits tightly oneof the openings through the block A and is forced therein. The body ofthe plug does not quite fill the opening in block A, and in theannularspace thus formed the piston C works freely,being guided bothinternally and externally by the plug D and the block A. The heads ofall the pistons are flush with the face of block A. This block isinclosed in a suitable case E, having door F and mouth-piece G, and thiscase forms a common sound-receiving chamber for all the pistons. Thewire of each magnet is soldered at one end to the magnet-core, and theother end is carried out through the plug D to the back of block A. Aconnection 2 is made with the core of each magnet, and is carried outthrough plug D to the back of block A. A pin (Z extends through theblock A adjacentto each circuit-controller, and on the front of theblock is connected by a wire 3 with the armature a and electrode 0,while on the back of the block it is connected with n1agnet-wire 1. Itwill thus be seen that in each circuitcontroller the coils of the magnetand the electrodes 11 e bear a shunt relation to each other, the contactof the electrodes short-circuiting the 1nagnet-coils and the separationof the electrodes throwing such coils into circuit. All theoircuit-controllers are connected in one circuit l 5. This connectionmay be any desired arrangement of series or are.

In Fig. 5 by utilizing the end connections 6 7 only the circuitcontrollers would be placed in one series, while by the use ofconnection 8 two series can be formed. Six binding-posts c (3 c c c eare shown, to which run connections 9 10 ll 12 13 14, dividin g thecircuit-controllersinto five series. By their use a simple series or anumber of arrangements in multiple series can be made. I prefer for aninstrument to be used directly in the line to employ a simple seriesarrangement; but with an induction-coil a multiple series ormultiple-arc arrangement would be preferable, although the particulararrangement in either case would depend upon the resistance of the lineand the resistance and power of the magnets.

The magnetrcoils form the definite units of resistance, which are throwninto and out of circuit by the circuit-controllers. This re sistance,however, is multiplied by the countereleetro-motive force of the magnetwhen the short circuit is broken, and a much greater reduction of thecurrent is produced than would be due to the introduction of theresistance of the wire alone, and the pulsations are sharpened by thepartial or complete neutralization of the static charge.

I propose using a much larger number of circuit controllers in myinstrument than shown in the drawings, although a lesser number could beemployed, and for long lines these are preferably arranged in series.

By the operation of the line-transmitter the current is thrown intopulsations which are in unison with the articulate sound-waves.

The pulsatory current is illustrated diagrammatically in Fig. 6. Theline 6 represents no current. The line f represents the current when allthe resistance is in circuit. The line g represents the current when theresistance is all cut out of circuit. The telephone-circuit beingconstantly charged by a current of one direction, at no time will therebe less current flowing than represented by line f. The pulsationscaused by the transmitter are represented by the zigzag line 71, varyingbetween the lines fg, since the pulsations will vary between points ofmaximum and minimum current.

\Vhat I claim is- 1. In a telephone-transmitter, the combination, withone circuit, of two or more sets of electrodes and definite units ofresistance located in shunt-circuits around such electrodes,substantially as set forth.

2. In a telephone-transmitter, the combination of two or more sets ofelectrodes, two or more piston sound-wave receivers, andelectrically-operated devices for automatically adjusting the electrodesand forming definite units of resistance which are throwninto and out ofcircuit by the movement of the electrodes, substantially as set forth.

In a telephone-transmitter, the combination of a number of sets'ofelectrodes and independen t controlling devices arranged at differentdistances from a central point, substantially as set forth.

at. In a telephone-transmitter, the combination of a number of sets ofelectrodes and independenteontrolling devices spirally arranged,substantially as set forth.

This specification signed and witnessed this 9th day of April, 188i.

EDIVARD ll. JOHNSON.

Witnesses:

War. II. I\.IEADOWCR()F'1, A. W. 'KIDDLE.

ICC

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